Unfortunately, one side-effect of more brain science is more breathlessly ominous news releases claiming that the Vice of the Moment—whatever it is this week—is mediated by the same brain circuits that mediate drug addiction! EVERYONE FREAK OUT

“People who frequently use tanning beds experience changes in brain activity during their tanning sessions that mimic the patterns of drug addiction, new research shows.”
-How Tanning Changes The Brain

“Oh, no!” we think. “Eating sugar, or getting a tan, is just like being a junkie! Who will rescue us from the evil clutches of Toucan Sam and Cap’n Crunch? Or the siren song of the tanning bed?”“Oh, yes!” the regulators think. “We can politicize this issue by stigmatizing people as ‘addicts’, taxing and criminalizing their behavior, and using the profits to finance the same efficient and effective tactics* we’re using to fight the War on Drugs!”

(* = sarcasm)

Anyway, I don’t want to turn this into a political rant. OK, maybe I do, a little, having just paid my taxes, and having seen this incredible sentence in a peer-reviewed scientific paper:

“…Even if the issue of indoor UVL exposure is successfully addressed, the successful regulation of outdoor tanning with natural sunlight, a major source of UV exposure, would remain problematic.”

Yes, our self-appointed guardians of public health are sincerely disappointed that they haven’t yet found a way to make the sun illegal.

OK, I’m done.

The Role And Limits Of Reward

Given the fearmongering in the popular press, and the ongoing confusion in the paleo community, I want to emphasize two important points about the role and limits of reward. The first I’ve mentioned before, but I’ll mention it again, because it’s important:

The brain’s reward system underlies all our motivations—not just the bad or “addictive” ones.

Any time we experience pleasure—any time we “like” something—that’s hedonic impact. (And it doesn’t require conscious appreciation of the fact.)

Any experience we “like” is capable of producing a “want” for more—incentive salience.

Organizing the refrigerator. Petting a dog. A long shower after hard physical work. Greeting a friend or a lover. Being complimented. Successfully finishing a long, difficult task. Seeing wildlife outside your window. It doesn’t matter whether that pleasure is from a physical thrill, positive social interaction, the satisfaction of a job well done, or direct chemical stimulation—it’s all mediated by (gasp!) the same circuits that mediate drug addiction.

This is why drugs that act on the reward system are so addicting: they can directly stimulate the feeling of having done something pleasurable without the user having to actually do anything.

And it’s very likely that we find pleasure in these actions for a reason: they were survival traits throughout evolutionary time. Stated in scientific language:

“Drugs causing pleasure and addiction are comparatively recent and likely reflect usurping of evolutionary ancient systems with high survival value by the gratification of contemporary hedonic indulgences.”

Therefore, saying that sugar, salt, tanning, or any other Vice Of The Moment “mimics the patterns of drug addiction” creates needless fear and distress, because it’s a tautology—it’s always true. It’s like saying “Did you know that your body is contaminated with DIHYDROGEN MONOXIDE?” Well, yes: that would be one name for ‘water’. (Read the Dihydrogen Monoxide FAQ for more information on this dangerous chemical.)

It’s also useful to remember that “addiction” is a matter of definitions and social norms. Even a behavior generally viewed as positive (e.g. cleanliness) is defined as pathological (obsessive-compulsive disorder) when practiced too frequently.

The second important point is easy to forget in the excitement of learning:

Just because a behavior we hope to change is signaled through the reward system doesn’t mean that it’s caused by a malfunction in the reward system.

I offer the following analogy: the reward system is like the dashboard of a car.

As the driver of the car, we know some basic things just by sitting in the driver’s seat: is it running? Is the engine making a strange noise? Does it respond to our use of the steering wheel, gas, and brake? However, there is a lot we can’t know from direct sensory input, and the dashboard (with its associated gauges and warning lights) is how the car lets us know important things like coolant temperature, oil level, our exact speed, and how much gas is in the tank.

Continuing the analogy, if the gas gauge reads “empty”, the problem might not be that the gas gauge is faulty. We might actually be running out of gas! Similarly, if the coolant temperature keeps reading high, we shouldn’t just blame the gauge, or the temperature sensor, and keep driving. (“You’re fat because you lack the willpower to stick to a diet”…”everyone is fat primarily because they are trying to entertain themselves with food”…does this sound familiar?) The fact that we learn of a malfunction through the dashboard does not mean that a malfunctioning dashboard is the cause of our car troubles!

Similarly, just because we have a problem (for example, excessive hunger) that manifests itself through the reward system (e.g. “wanting” so much food that we start gaining fat), that doesn’t mean that a dysfunctional reward system is the cause of our hunger! We could have any number of metabolic, endocrine, or nutritional issues to which excessive hunger is a perfectly reasonable response. (A few examples: diabetes, hypothyroidism, vitamin insufficiency, some antidepressant and antipsychotic drugs.)

It’s tempting to explain away every aspect of a mind-bogglingly complex homeostatic system, like human metabolism, in terms of the few parts we understand. The result even looks like science, because of all the footnotes! However, I’ve found the temptation is best resisted.

Conclusion

The brain’s reward system underlies all our motivations—not just the bad or “addictive” ones. Any choice we make that isn’t purely a rational product of our forebrain likely involves some measure of reward signaling.

Just because a behavior we hope to change is signaled through the reward system doesn’t mean that it’s caused by a malfunction in the reward system. The reward system is the conduit by which our wants and needs are communicated to our conscious mind: it’s not the cause of our wants and needs.

Loved this article but I’m wondering….how does the basal ganglia and “habit centers” of the brain fit in? When a behavior becomes habituated and no longer may even stimulate the reward centers in the same degree, but becomes either unconscious and scripted behavior, or more to avoid the pain of not having the substance than the pleasure of having it? What do we do about that pesky basal ganglia?

@Elliot – lol, me too! Figuratively, of course… I try to avoid giving my coworkers the (true) impression that I’m excessively strange. Oh, and I’m not supposed to be on the internet. Oops!

Thanks for the solid rebuttal… I had been seeing these types of articles seemingly everywhere, and my instinct was to ignore them, but it’s good to have some science to back up why I’m dismissing them to friends and family.

Bastiat was awesome! Frankly, I prefer “What Is Seen And What Is Not Seen”, 19th-centuryisms and all, to Hazlitt's rewrite of it in “Economics In One Lesson”.

Leslie:

That's a great website, and it reminds me that I need to read Temple Grandin!

The point that the subcortical structures of the human brain, including the reward systems, are essentially identical to those of other mammal brains is well-taken and extremely instructive. (I thought about bringing it up myself, but decided that it would make the article too long!) Our “conscious mind” (i.e. executive function, i.e. the forebrain) sits on top of these older systems: it doesn't replace them, it works through them and is mediated by them!

Judy:

If something only makes it to the basal ganglia, it's not really a “decision” in any meaningful sense of the word. (I'm going to deliberately ignore the question of whether anything that happens in the brain is truly non-deterministic, i.e. “do we really have free will or just think we do?”)

For instance, when we jerk our hand away from something hot, that's a reflex action that doesn't even make it to the brain! There's no “decision” to be made. (Overriding that reflex is a pre-decision: we have to decide beforehand that we're going to ignore the pain and override the reflex.) Similarly, something made at the level of the basal ganglia doesn't make it to any part of the brain we think of as “deciding”: that's why we call it a “habit”. (And, as I mentioned back in Part VI, the experience of learning can modify our “likes” and “wants”.)

Like I said above to Leslie, our brains didn't just get bigger and more complex: they accreted, with the newer systems being built on top of the older systems, and working through them. My oversimplified understanding is that stimuli basically get kicked upstairs until a brain system capable of dealing with them produces some sort of response…and the process of “learning” or “training” allows lower-level brain systems to deal with specific stimuli instead of kicking them upstairs (cf. martial arts training turning punches, blocks, and throws into reflexes).

Marilyn:

My understanding is that the real problem isn't global temperature: it's ocean acidification (and consequent marine life dieoff) caused by a rise in atmospheric CO2. Blocking out the sun seems like it would just reduce ocean productivity, making the problem even worse.

I'm glad my perspective is helpful to you!

eddie:

People sometimes ask “Can't you write more simple articles like this?” Well, it wouldn't sound so simple if I hadn't previously explained the science!

TGC is a book I keep coming back to…and I'm the one who wrote it down. There is much important knowledge packed into very few words. And I still miss Gryka.

Elliot:

I hope it justified the anticipation!

gallier2:

Arguments from authority can be a symptom that someone doesn't understand the problem quite as well as they think they do. So can excessively slippery arguments: if someone has to continually fall back on “no, that's not what I meant, you don't understand, it's more complicated than that,” it's possible that they don't really understand the problem themselves.

js290:

It's absolutely true that invoking the conservation of energy is a tautology. (Cue the classic essay On Taubes And Toilets.)

However, I wouldn't use the word 'specious': the brain's reward systems are real, and there exist measurable phenomena that need explaining. I think there's been both confusion and oversimplification of their role and limits — and it's resulted in either a return to blaming sloth and gluttony, or (as Paul Jaminet pointed out) it becomes a protean catch-all for results that don't agree with one's hypothesis.

Most of what passes for nutrition writing is, frankly, alarmism. And please feel free to forward my articles to friends and family — they're written to be understandable for people who aren't already “paleo”.

I’ve recently discovered another hunger / desire for food drive – menopause
Maybe this is why women put on weight at this time of life (certainly hormonal changes don’t help) but I’ve just developed an intolerance to hunger!

My observation too with children is that they differ an huge amount in how much pleasure / reward they experience from eating. My daughter loves food, my neice loves food, they revel in taste and smell and sheer enjoyment from eating. My son on the other hand is driven to eat through a growth spurt – but to him food is just fuel. Same with another niece. The food lovers struggle with weight, the fuel needers don’t.

I love this post – just as I love all your posts – but I have an additional reason to appreciate this one. My youngest son just turned 17, and while we’ve had many discussions about drugs and alcohol in the past (he’s the youngest of 5; there’s a lot of “been there, done that” in all this), most of them have ended in, “and if I find out you’ve been doing any of this, I’ll have to kill you.”

My kids do not take that threat lightly.

Anyhoo, being the good libertarian family that we are, he’s begun asking me questions about the dubious illegality of controlled substances lately, in what I feel is an attempt to find out if I’d have to kill him if they were legal (he is, after all, 17 and I’m always quick to point out that if he were to get arrested for possession I’d let him rot in jail). I was thrilled to be able to show him the quote in this post saying what makes drugs addictive (and dangerous) is that they stimulate the reward center of our brains without us actually having to DO anything. He’s the sort of kid that kind of logic appeals to, so – THANK YOU.

Don’t judge, y’all…I’m a menopausal woman desperately trying to get her last kid raised and on his merry way without screwing up too much in the process.

Julianne, that’s interesting. In Susan Allport’s The Primal Feast, in a chapter entitled The Hungrier Sex, she observes that females innately have a different relationship with food than males … for a whole lot of reasons discussed in her book. Primary one being the bigger investment in reproduction than males–from having all their genes in one single egg to the vulnerability to starvation while rearing offspring. Practically, foraging is something a female carrying an infant can do more easily than hunting. It has even been posited that optimal foraging lead to monogamous behaviour.

From my research I’ve learned there have been several studies done since the 60’s on “free will” and from what I’ve gathered, free will is supposed to be fake. Apparently there is a half second time lapse between when a “decision” is made by the brain and when we become consciously aware of said decision. A more appropriate name could be called “free hell-no” bc it would seem that the only choice we have at that point is to stop an action. How true any of that is, I have no idea. Sorry I don’t have any literature to cite, it’s been awhile since I read any of that. Anyway, thanks again for disseminating clarity; it’s something I look forward to every week after being surrounded by stupid cows all day-I work directly with the public….
One thing that I would like to see you write more about is something you touched on briefly at the beginning of “Big Brains….” and that is teleology. I know your process is intense but I believe that teleology is an insidious mental trap that is super easy to fall into. Hell, just take all existing religions for example….how humans love to superimpose our conscious awareness on EVERYTHING. If I had more time, I could devote an entire blog to the subject.
Thanks again JS
Cheers
Oh, and for anyone interested in a political discourse(which I am now after reading this) you can’t do much better than Keoni Galt @ The Hawaiian Libertarian.

This just in, folks. The same neural circuits are activated by making love to your partner as are activated by looking at porn! Be very careful about your love addiction with your significant other, spouse, mistress, bedmate!

“…Even if the issue of indoor UVL exposure is successfully addressed, the successful regulation of outdoor tanning with natural sunlight, a major source of UV exposure, would remain problematic.”

I have read a bit of research in my field, if I were to read something like this, I would interpret it as being said with tongue firmly in cheek. If I were to write it, the purpose would be to forestall those with the impulse to regulate.

The same Compass of Pleasure book I referenced above talks about that phenomenon. In one study women were connected to neural imaging devices and given chocolate milkshakes, which both produce a significant dopamine response and are easy to consume when you’re strapped into a bunch of sensors and can’t move much.

The act of eating is associated with dopamine release from the ventral tegmental area to various target regions in the brain which produces the sensation of pleasure and reward. Different foods produce different levels of dopamine release.

Interestingly, mere anticipation, prior to the actual consumption of food, is also associated with dopamine release and can actually be a stronger response than that produced by the act of eating.

In other studies, overeating, particularly with junk food, has been associated with a blunted response to dopamine via things like decreased D2 dopamine receptor density in the dorsal striatum.

The study divided the women into obese and non-obese and found that the obese women had greater activation of the dopamine reward circuit during anticipation but blunted dopamine response after eating. Thus, the experienced increased craving with a simultaneous decrease in reward. Chasing the chocolate dragan, essentially.

So your observation that the food lovers struggle with weight while the fuel needers do not has a verifiable neurological basis.

What to do with that observation is another matter entirely, but is likely to be controllable to a large degree.

That habituation induces an intricate dance of long term synaptic potentiation and depression of dopaminergic, glutamatergic and GABAergic axons through a wide array of inter-related brain regions as well as dendritic spine overgrowth in the medium spiny neurons of the nucleus accumbens.

I think it’s a little too complex to be conveyed in a blog forum to be well understood, but here is a good paper on it:

Free will has been a hot topic lately and many leading psychologists and neuroscientists share the opinion that it is anywhere from non-existent to at least not nearly as pervasive as is commonly believed.

Most recently Sam Harris published a short book titled Free Will making a case pretty close to the former.

David Eagleman’s book Incognito – The Secret Lives of the Brain provides a fantastic account of the wide array of thought processes which actually occur outside of our conscious awareness and is much more thorough than Free Will.

Daniel Kahneman also recently published an outstanding book summarizing much of his life’s work (as well as that of his late colleague Amos Tversky) called Thinking, Fast and Slow. It details an astonishing array of heuristics and biases we are prone to and how shaky our self perceptions of rationality often are.

I suspect the hormonal changes are a primary cause of the increased hunger…but as that’s not an area of my expertise, I can’t make any judgments.

Your comment about children is interesting and unsurprising: it’s well-established that some people need more stimulation to reach the same levels of dopamine (or whatever metric you’re measuring) as others (“daredevils”). The reward systems are extensively studied and documented, just not with food and hunger per se…but the applications to our behaviors around food and hunger are obvious.

However, we must be careful about assuming which direction the causality runs. We know that “hunger is the best spice”, and that satiety is driven primarily by nutritional status (including the ability to access stored nutrients). Do the children derive more hedonic impact from food because their reward system is harder to activate? Or do they derive more hedonic impact from food because something about their metabolism (e.g. lack of metabolic flexibility) leaves them hungrier?

Jan:

I’m glad my explanation was helpful!

I like it because it’s non-judgmental. It doesn’t claim that drugs are intrinsically evil (false), that they’re no fun (false), or that using them makes you a bad person (false). It does explain why so many people use them and enjoy them — and why using them can be dangerous.

Leslie:

I generally refrain from ev-psych speculation, but it is true that a man only has to be “not starving” for a few months in order to father a child. A woman has to be well-nourished for years in order to become pregnant, carry to term, and nurse a child.

You might be interested to read “The Old Way”, linked in my Recommended Reading list. Among the San, meat and other hunted foods are basically communal: they’re brought back to camp and everyone gets some. However, when the women are out gathering, it’s finders keepers: whoever digs it gets to eat it or feed their husband with it.

Daniel:

I know the studies you’re referring to. It’s not so much that we don’t have the ability to choose — it’s that this ability is somewhat slow, being a function of the forebrain and having to (as mentioned above) go through all the other layers first. As a result, we’re usually not exercising rational choice: we’re usually acting by rote or by emotion and rationalizing the decision we already made.

This is why I enjoy writing articles and responding online: I can carefully consider my words before publishing them!

Aaron:

Wasn’t that the intellectual basis of the Victorian era? (Though stated in less clinical terms.)

Chris:

I would hope so — but the tone of the rest of the paper (and its very title, “UV Light Tanning as a Type of Substance-Related Disorder”) caused me to take it seriously. And NSW, a province of Australia, has already banned tanning beds.

I’m glad you find gnolls.org useful! I do my best to make it a reliable, information-dense resource for everyone.

I love that you don’t write “simple articles.” I come here because you present good information and critical thinking, realizing that your readers are intelligent and capable of understanding complex ideas, albeit each at a slightly different level. As well as having something to read that fits my interests and philosophy, it’s nice to find something on the internet that challenges me and gives me something real to learn aside from funny little facts and statistics. Thank you!

Thanks for the plug! And when you do your CT, be mindful of the additional DHMO exposure.

Craig:

Though I stay out of that level of detail in my articles, that's an excellent paper on the biochemistry of reward.

I've never read The Compass of Pleasure — but I cited one of the papers you mentioned (“Weight Gain Is Associated with Reduced Striatal Response to Palatable Food”) all the way back in 2010, well before reward became a hot issue in the community. I'll put TCoP on my to-read list.

“What to do with that observation is another matter entirely, but is likely to be controllable to a large degree.”

Exactly. Most of the reward literature deals with drug addiction — which is a much cleaner case to study, because the human body has no intrinsic requirement for heroin or cocaine. Indeed, studying that literature allowed me to understand the reward systems much better!

However, since we do in fact have continual and complex requirements for food, the causality of appetite can run either direction.

It's interesting that our reward centers are doing what one might expect — lowering the hedonic impact of food in the obese, who presumably don't need as much of it — but instead of consuming less, some people consume more in order to maintain the same level of hedonic impact in their life! This suggests many interesting ways to address that particular problem, and it helps explain the correlation between depression and obesity (people who aren't getting pleasure from other parts of their life seeking to replace it with food).

I have a copy of Incognito but haven't read it yet, so I'm glad for your vote of confidence.

Kate:

You're welcome!

There's a lot of cynicism out there…but I prefer to assume my readers are reasonably smart people who place value on good information.

It's easy to intimidate with a forest of citations and qualifications and claim, upon inquiry, that any point of dispute is too complex to explain to the layman — but I usually find that if I can't produce at least a top-level explanation of how something works, my own understanding is probably incomplete. “He who teaches learns twice,” etc.

i tend to believe that a person who cannot explain things to a layperson does not really understand what they are talking about.
and the use of excessive jargon and technical language always annoys me in this sort of situation.
(i found this when working at the tax office and overhearing another advisor talk to a member of the public)

Chris: Im more than familiar with those gentlemen; and I have my own contentions with all of them. And agreements. Alas, I haven’t the time to really get in depth so I’m regulated to being a generalist- nothing wrong with that either, it has served me quite well.

JS: I have my own opinions on heuristics…..and emotions. And false thinking. Personally, I prefer eastern meditation techniques that have allowed me to stay aware of the entrained thought patterns (conditioning) and it helps me to choose NOT to run on automatic pilot. This really should’ve been my original comment…..lack of sleep is a killer especially for those of us that have circadian rhythm issues. Can’t stress the importance of sleep enough, especially for cognition. As you’ve put it before tho, we live in an evolutionarily discordant age, so we must do the best we can. And I do.
Cheers

Interesting! Now that I'm more familiar with how the brain works, I bet I would get a lot more out of Eastern mysticism, because I would be able to cut through the fog and understand at least some of what they're trying to do.

Sleep is indeed hugely important…I remember reading a study years ago which showed that the speed improvement on a specific cognitive task the next day was proportional to the number of hours of sleep above six! (I think it maxed out at eight or nine.) There's also some solid literature on the importance of exercise to cognitive function, and the dramatic improvements which occur immediately after exercise.

JS: If you are interested in reading about eastern philosophy and the mind you will not do any better than The Ten Paradoxes. It’s a short series (but long books) written by a westerner under the pen name Master Nomi. He takes all that mystical crap out of it and writes it for our very mechanistic western minds. Highly recommended. One thing I can’t stand is mystical anything. All it does is confuse and make for a master/ student dependency that is reminiscent of the catholics insistence that you go through a priest for forgiveness of sins even though there is literally no mention of that in the bible. In Mahayana Zen, they insist that there is a “direct transmission of mind” leading from the Buddha all the way down to whatever fat belly they have decided is his modern “spiritual ancestor”. Really? Prove it fellas. But enough of that. Seriously.

Sleep is my other panacea, besides steak….the sleep studies are extremely insightful especially as they relate to bedtime. There is like a sweet spot for bedtime(earthly location coordinates considered) whereby the more hours before midnight you go to sleep the better quality the sleep. There is a sliding scale of diminished quality the later you crash. Basically sleeping later does nothing. What I’m researching now (one thing of many…) is biphasic sleep patterns in early man. From what I understand, before artificial light we all slept in two chunks: from dark(ish) till around 1 and then from about 3 till sunup. Mark Sisson did one post on it a while back but there is quite a bit of literature out there on the subject.
Cheers

Fantastic article, JS. And I will even forgive you for calling NSW “a province of Australia” (it’s a state)

On a serious note, this is exactly the problem with trying to explain away the normal physiological functions of the body by brain pathways. When the thermometer shows it’s freezing in the house you don’t blame the thermostat. The likelihood is that it just relays information. Unless there is proof of dysregulation, which at the moment seems to be the event further down the line: your reward pathways are obviously at fault because you are overweight.

Hunger, being a physiological response to inadequate nutrient status, should first and foremost be treated as a normal phenomenon. Is it possible that incessant hunger is caused by reward pathway dysfunction? Absolutely. But probably unlikely in the majority of people who experience it.

@jeffery of troy:
“Maybe free will is neither automatic nor impossible, but something that has to be achieved”

Huh? Free will by any definition couldn’t be “automatic”, and whether it’s possible or not isnt really even part of the discussion. The current debate in the scientific and philosophical circles is over where biology ends and conscious awareness begins(not to mention whatever the hell “awareness” really is) Trying to “achieve” something held within the mind is like trying to step into the same spot in a river twice. Not gunna happen.

I'm not convinced that sleeping later does nothing…it's certainly better than not sleeping! Perhaps it's a light thing, as I've blacked out my sleeping area pretty well.

Anastasia:

Great to hear from you…and congratulations on the M.D.!

“Hunger, being a physiological response to inadequate nutrient status, should first and foremost be treated as a normal phenomenon.” Exactly! If we don't understand why people get hungry, we can't possibly understand why they overeat…it's not like people suddenly decided “I hate being slim and healthy. Frankly, I'd rather be fat” sometime in the 1980s.

Jeffrey, Daniel:

Thus the reason I decided not to open the “free will” argument…it's a whole another topic in itself!

“I’m not convinced that sleeping later does nothing…it’s certainly better than not sleeping! Perhaps it’s a light thing, as I’ve blacked out my sleeping area pretty well.”

Good call. I used to work strictly nights years ago and learned to black my room out too. I never quite got used to working nights but there was a massive difference in sleep quality no matter what time I actually crashed or woke up. Hormones, hormones, hormones.

I still sleep in a cave to this day. I was visiting a friend of mine in Austin a couple of months ago and slept on his couch; I slept like 10 hrs straight but his sliding glass door has those crappy vertical blinds that couldn’t keep light out if you blew up the sun. Felt like total ass the next day.

“The point that the subcortical structures of the human brain, including the reward systems, are essentially identical to those of other mammal brains is well-taken and extremely instructive. … Our “conscious mind” (i.e. executive function, i.e. the forebrain) sits on top of these older systems: it doesn’t replace them, it works through them and is mediated by them!”

Somewhere along the way, it was decided that we are *not* animals, we have a soul and make all our choices consciously, with our big brains. This I think, has been the cause of many a mistaken idea about why we do what we do — most notably: how gluttony and sloth lead to obesity.

I agree that there is a very great deal to be learned by accepting our part in the natural world. I am convinced that just like every other animal we have innate abilities: to not only manage our energy balance but also our nutrient balance… without the need for kitchen scales or nutritional labels.

As an example: consider the craving of a pregnant woman. I dare any man to dismiss these 3am cravings with a “go back to sleep, it’s all in your head!” Clearly there is some biochemical need being communicated.

JS:
Maybe we are going in circles here and I do agree that the heavenly bodies are part of our heritage, but perhaps it’s our almost complete disconnect with natural light and reliance on artificial light that clouds the issue a bit.
There are plenty of subjective accounts of people that were cut off from artificial lighting for months at a time and had only the sun, moon, stars, and camp fires for light. After a short period of adjustment, they state that they felt “reset” and rose with the sun and crashed with it too. And of course they all state the same positive effects of a circadian rhythm reset and everything; increased energy, etc.

I think those of us in this paleo camp understand the importance of healthy, natural sleep, sunlight exposure, and minimal nighttime exposure to blue light whether it be from computers, light bulbs, or whatever.

I agree that the popular view of hunger is basically religious, and I made a similar point in Part VII: “Even the irreligious tend to take the theological viewpoint on hunger: the desires of the body are sinful, and exist to tempt us into gluttony and sloth.”

“I am convinced that just like every other animal we have innate abilities: to not only manage our energy balance but also our nutrient balance… without the need for kitchen scales or nutritional labels.”

Absolutely! If humans required those things to eat properly, how did we survive for millions of years without them? Were we deficient in lentils and brown rice ever since the Pliocene, and just never knew it? It seems unlikely.

I'm glad you found the article useful and informative. Do stick around!

Daniel:

I'm not really arguing with you, and I apologize for sounding like I am. There's just a currently-fashionable dogma in the Paleo community that it's absolutely unhealthy to do anything but go to bed early and wake with the sun. As the article Pete linked suggests, different people have different sleep patterns (some of which are determined genetically) — and the technology of houses and blackout curtains allows us to simulate night relatively effectively. (Though simulating daylight isn't so successful.)

There's also the interesting fact that when people are completely decoupled from natural lighting and clocks, and allowed to sleep/wake when they wish, they tend to run on a “day/night cycle” somewhat longer than 24 hours.

“I think those of us in this paleo camp understand the importance of healthy, natural sleep, sunlight exposure, and minimal nighttime exposure to blue light whether it be from computers, light bulbs, or whatever.”

Quite true. I also suspect that the constant 120Hz flickering of fluorescent tubes with magnetic ballasts isn't good for us either, though I have no evidence for this other than my personal dislike for it.

JS:
No apology needed man, keep doing your thing. Funny tho, bc I kept thinking you thought I was being argumentative. We need to hunt and kill dogma as much as possible. There may be many things that are correct and true, but once things become “gospel truth” we get into trouble. We need to retain our ability to question our own conclusions in the greater search for truth.

I’ve never backed down from a fight be it verbal or physical and I love a good argument anyway.

I like this topic. I have been trying to understand Guyenet’s reward theory but there is something off about it that I can’t quite put my finger on it. Just observing myself I can see that there are foods that can trigger a limbic reward/pleasure center, and they aren’t always the usual suspects. But to blame that as the cause of obesity seems strange. It may be a pathway, an entry point, one of many, but the sole cause? As if just avoiding things that trigger pleasure centers in the brain can fix it? This seems too simplistic, too Puritan and misses the gray areas. The exact gray areas you point out when you say that “the brain’s reward system underlies all our motivations—not just the bad or “addictive” ones.”

I understand well! However, I'm trying to keep gnolls.org a calmer and more welcoming place. There are plenty of blogs devoted to arguments.

Diane:

Exactly. It's a classic case of mistaking one part for the whole. The human body is a wondrously complex web of interacting homeostases…claiming that one of them is the primary cause of obesity, given all the other factors we know play a part, has always seemed bizarre to me.

JS:
I’m glad you feel that way; I’ve stopped reading several blogs bc of contentiousness(they were deliberately written like that.) Anyway, you do just fine making everyone feel welcome.

One thing I need to do is take more time with responses and choose my wording more carefully. Nuance is difficult over the interwebz so I could stand to refine my posting skills to avoid unnecessary arguments.

JS, hi! In both of our absences, I missed you. Hope all is well. Additionally, so glad to see more re: hunger, and also what’s following re: your incredibly ability to convey complex ideas to a wide audience.

Re: our discussions of my hunger in the past. I want to tell you that they are waning. I’ve put on weight. That’s made a BIG difference. I’m also eating carbohydrates, which is actually helping. Not the fructose, processed sort, but the starchy sort. At least I think it’s helping. And finally, I’ve been trying (though failing… if you ever end up over at my new site, you’ll hear all about the things that I’m wrestling with, though I don’t state that it’s a personal battle explicitly)… so right, I’ve been trying to sleep more. I think increased sleep and increased fat mass and also some carbohydrates are helping me out with my leptin levels. Just thought I’d fill you in, and say I’m excited that you returned (though I know it was a while ago) and drop a hello, too.

Great to hear from you again! You're on a massive tear over at Paleo for Women, and I confess I haven't been able to keep up with all of it.

Your weight experience is interesting: both myself and others have found that our bodies and metabolism have continued to slowly change for a year (or more!) after going Paleo. So I think the emphasis many people have on “losing weight fast” may be counterproductive: I view lower fat mass primarily as a side-effect of a healthy metabolism. As I've said to others many times: your body didn't get screwed up in a month, don't expect it to fix itself in a month.

Consequence: I suspect you'll do much better in the long term by eating (and sleeping) in a way that addresses your health issues first…and then, once you're metabolically functional, seeing what happens to your weight, and perhaps choosing to address it if it's still not going where you want. You seem to be on this path already, which is good.

Anyway, I'm glad to hear that you're doing well, and it's great to see you posting again. And yes, I will absolutely be at AHS this year…in fact, I'm presenting! So I look forward to meeting you in person.

YES, a “tear”–oh my goodness I have never written so many words in so short of time in my entire life, esp. considering I just finished up the finals period here in my philosophy program, too. Many words, but it’s all so exciting, I can’t really stop.

You are absolutely right, and I was a complete idiot for several years, wanting to meet society’s standard of attractiveness before achieving good health. I am a firm believer now that even the thought of body-hatred or body-worry causes enough stress and negative cognitive behavior that weight loss/being healthy in general is significantly impaired. The whole vanity race… well, I’m as done with it as I can possibly be anyway. It’s not worth it, not for anyone. Just stupid, stupid, stupid.

[…] leptin signals under a bus are stress, loss of sleep, problems with neurotransmitters, or nutrient deficiencies. Under the influence of these factors, or perhaps several of them in conjunction, it becomes […]

[…] enough the first time round and no more plausible for being resurrected and offered again. As J. Stanton points out, reward explains all of our motivations. As it relates to obesity, I always thought it wasn't much […]

I always wondered about this: Since losing a ton of weight ( low carb/paleo of course), for the first time in my life I can be outdoors without a shirt and not feel like a freak. Now, since spending a lot of time in the garden or swinging kettlebells or playing with the dog (& always around mid-day) I have yet to get a sunburn or even a decent tan. My left arm doesn’t even tan from driving. This has been going on for the last two years (the weight loss years)- Could a high fat diet prevent skin burning? Observational it does. Any thoughts?

One of our more scientifically minded folks might well give us the skinny here, but as far as I understand it, cholesterol metabolises sunshine into vitamin D. You don't get burned, quite the opposite – you gain a lot from sunlight, but only through cholesterol … which comes from real fat.

I love how you say you play with your dog. Playing is so important! Fun, activity and engagement with another creature; particularly a creature of another genus is really primal.

No one knows for sure, but it's a common finding. I suspect it has to do with the decrease in PUFA and the increase in SFA in our diet. Our cell membranes are all made of phospholipids — two fats stuck to choline, or a similar molecule with phosphorous in it — and, as any chemist can tell you, a saturated fat is a far more stable molecule than a polyunsaturated fat with multiple double bonds. This would leave skin cells far less prone to oxidative damage from sunlight.

This hypothesis is consistent with the fact that skin cancer rates continue to climb over the last three decades, despite increased sunscreen use and lower sun exposure.

Paul:

Cholesterol is indeed the substrate for vitamin D synthesis (which requires UV light), but I'm not sure that affects your skin's production of melanin or propensity to burn.

Of course, we could just see it as … “there's a big old sun up there and we've been living under it for a few million years … if it really was bad for us, we would have frizzled up years ago”. The sun is the very reason for life on this planet – we have developed ourselves as humans to be averse to the sun by deviating from a natural diet. Eat paleo … live as intended under the sun, taking all the life-giving benefits it gives.

JS, does food reward adequately explain the calories out component? That is, if we accept that metabolism can be slowed by restricting energy input, then it stands to reason that metabolism can be increased by increasing energy input. In other words, energy input and output are coupled; they can’t be treated independently. So, if one is to argue that highly palatable foods cause excessive energy input, would they not also have to explain why those same palatable foods reduce energy output? Maybe I missed this part of the food reward theory?

First, I don't even like using the term “food reward”, because it implies that “reward” is a property of food itself, primarily mediated by its taste. (Or by a magical property called “hyperpalatability”, typically used as shorthand for “food we tend to overeat”. Yes, that's a circular definition.)

In reality, “reward” is a subjective property assigned to food by an individual — and the evidence is that it's primarily mediated by our own nutritional state and cultural preferences, not by the taste of the food itself. I've laid out some of the evidence in previous installments, and I'll lay out much more at my AHS presentation.

Moving on to your question: all that the reward system can do is determine, to some extent, what foods we choose to eat (e.g. “calories in”). One key difference between myself and some of the more zealous proponents of “food reward” is that I see no evidence that hunger and reward trump biochemistry!

For instance, it doesn't matter if you've eaten sugar because you really like Mountain Dew Code Red, because your mother guilted you into finishing her huge plate of spaghetti, or because someone said you should eat 30 bananas a day. If you eat more glucose and fructose than your liver and muscles can store as glycogen, your body will (among other things) uprate thermogenesis in order to try to burn off the excess. So the fact that reward can explain some fraction of “calories in” doesn't change what happens once we ingest them…and the evidence is clear that “calories in” and “calories out” are not independent quantities.

And so on. As Peter at Hyperlipid says, “I rather like biochemistry.” So do I — and I disagree in the strongest terms with comments like “Everyone is fat primarily because they are trying to entertain themselves with food, and it has bollocks to do with insulin or “damaged mitochondria” or micronutrient deficiencies.” This mistakes the map for the territory: as I said above, “The reward system is the conduit by which our wants and needs are communicated to our conscious mind: it’s not the cause of our wants and needs.”

What happens to food once we eat it is biochemistry, and it has everything to do with insulin and mitochondria and micronutrient deficiencies — as well as leptin, CCK, PYY, secretin, and a host of other hormones and peptides and complicated interacting homeostases between the trillions of cells in the human body.

I rather like biochemistry too. All myths and misconceptions fall away in light of biochemistry.

I think there is more to biochem than we realize. Our place in the world can be revealed by it and perhaps so can our attitudes and outlooks.

No amount of medication, meditation, positive thinking, etc., can “fix” us if our biochemistry is all screwed up. That’s why so many people have so much success with diet alone.

I know my attitude shifted drastically in the positive once I fixed my biochemistry.

With every theory that comes to pass regarding health-whether mental or physical health(SAME THING)- I always check it up against what we know SO FAR about biochem.

There’s no reason to over think this stuff anyway: eat fatty meat, don’t eat birdseed, drink water. Organs, bone broths, and some seafood are nice too(SASHIMI!!!!). Oh yeah, and I guess some veggies for color…..if you want.

One of the unfortunate consequences of overcomplication is that it leaves us vulnerable to being sidetracked by the infighting and status-seeking that's become so prevalent in the online community of late. “There must be SOMETHING MORE I can do to my diet to make it EVEN BETTER”… Well, maybe not! I think some of this “Paleo is too limiting” talk — and its alternative, “You're doing it wrong” — isn't adding any knowledge, and it's confusing a lot of people.

Yes, the brain is involved in biochemistry: it's part of most homeostases, because that's why brains exist — to help coordinate the function of the trillions of cells in a body (human or otherwise) so that they function as an individual, not as an undifferentiated soup of competing cells! (And lest we forget, the brain and nervous system are made out of cells, too.)

That being said, the trillions of cells in a human (or any other animal) aren't mindless hand-puppets of the hypothalamus, or any other part of the brain: each one has its own energy needs and expresses receptors according to them (e.g.: “insulin resistance”, which is usually the result of trillions of muscle and liver cells saying “No thanks, we're full of glycogen already”)…not to mention performing its own unique function (e.g. excreting digestive enzymes, conducting nerve signals), excreting its own waste products, etc.

“Do the cellular processes work the same irrespective of signals from the brain?”

Yes and no. Yes, because each cell is its own little biochemical unit, with its own function. No, because most cells are responsive in some way to hormones, peptides, and other signaling molecules (including innervation), which the brain is often involved in maintaining the balance of.

We like to think of the body as a car and our brain as the driver. Unfortunately, it's far more complicated than that!

Great series, especially the piece on hyperpalatibility being foods that simply don’t provide satiation and satiety (even though they might not even taste that good [i.e. have only moderate hedonic impact]). It also explains why Paleo works so well, as I don’t have to make an effort (exercise willpower) to limit great-tasting foods like organic beef, eggs, grassbutter, peaches and berries, because they satiate and sate and thus, reduce my appetite at the right moment because these foods are nutritional.

As for the brain chemistry stuff:
I don’t think it’s neccessary to pussy-foot around the issue like that, though. Mild addictions run rampant in our society nowadays and most people know it about themselves, but just refuse to face the facts as their life remains fairly functional in spite of their addictions. We need a more mellow approach to this and that means every single person has to start making addiction a regular part of their vocabulary and more importantly: a matter-of-fact aspect of their own behaviors. The attitude must be: Everyone has addictions and it’s no big deal. But even though it’s no big deal, it’s still something that needs to be adressed, as addictions have negative long-term impact on our lives.
I think we agree on this ‘no-stigma’ on addiction approach, but in my opinion you’ve got to say it like it is, not walk on eggshells around the issue.

I'm glad you find my explanations helpful! It's easy to make “Science!” say almost anything we want through selective citation: it's much more difficult to make sure it's useful and relevant to our own lived experience.

I'm curious how you believe I'm “pussy-footing” around addiction. Addiction lies on a spectrum of behaviors, all mediated by the same brain circuits — so defining something as “addiction” instead of “normal behavior” is very much a definition of social norms. For instance, we consider a daily glass of wine with dinner to be normal behavior, but we do consider daily usage of cocaine to be “addiction”. However, if you're in the Peruvian Andes, however, daily chewing of coca leaves is normal behavior! And so on.

Basically, once your habit starts to impact your ability to conform to local norms of behavior, we start calling it “addiction”.

Another example: continual hand-washing and hand-sanitizing was considered OCD twenty years ago: now wet-wipes and buckets of Purell are everywhere, and their use is strongly encouraged!

If that's pussy-footing, then I guess I need to understand how and why.

I hope this isn’t a dumb question I have diligently plowed through all of your series on hunger. I may have missed or not understood something. I have kind of a grasp on satiety vs. satiation. Why, (provided we have a good diet that includes all essentials for satiety, AND we are adapted to burning fat as a fuel source AND we have excess body fat available AND our diet includes enough protein)do we get hungry at all? I certainly get hungry less (I eat 2 good-size meals a day) but I still get hungry at times even though I consume a lot of protein and have plenty of body fat for fuel. Thanks.

We get hungry every day primarily because there are many nutrients our body can't store.

Protein is the most obvious: we need a certain amount of complete protein each day, or we'll start cannibalizing our own muscle mass to get it. Many vitamins and minerals (such as Vitamin C, AFAIK) are not stored either, and we must consume them regularly in order to maintain health. And we have a very limited facility for storing carbohydrate…perhaps 50-100g in the liver, which must power both the brain and our red blood cells (among others), and which must be continually replenished somehow. (If you eat nothing, it will be replenished via breaking down muscles for protein and turning them into glucose via gluconeogenesis.) People on hunger strikes die of muscle wasting and lean tissue atrophy long before they run out of body fat.

So even if we have plenty of calories available, in the form of body fat, we still have not decreased our requirements for protein and many micronutrients.

Yes! The light bulb finally went on! I had been a little frustrated because my weight and body fat (145#, 28%, 52 y.o.) had plateaued despite dedicated dairy-free paleo and regular exercise. I know I’m eating enough calories, but was still feelig very hungry at times. When I try and restrict calories further, I get starved and binge (but on paleo stuff!)

I eat almost no fruit on a regular basis, but crave it occasionally. Your explanation makes that make sense if I need the vitamins and minerals. Thank you so much for geting back to me on this!

Seaweed and beef soup? Chilli, garlic and ginger? What a ride! Iodine kick, good, real food and a tasty little pre-dinner slurp. Raw beef, naturally, which sliced, cooks in the hot broth. I get a big bag of dehydrated sea vegetables which lasts ages – the tiny amount balloons out into a full pack of seaweed.

Your point though is bang on the nail! Listen to your body and then think – we have big brains and can think around problems. I crave X because it is made up of A, B and C. It's the C that I want, so eat C.

Yes, I should theoretically be able to get along without supplements…but often I'm not eating all the beef liver I should, and it's tough to get magnesium when the water treatment plant is stripping out all the minerals from the groundwater. No, I don't go wild on them…but there are a few which make sense for me and my life.

Support gnolls.org by making your Amazon.com purchases through this affiliate link:

It costs you nothing, and I get a small spiff. Thanks! -JS

.

Subscribe to Posts

Gnolls In Your Inbox!
Sign up for the sporadic yet informative gnolls.org newsletter. Since I don't update every day, this is a great way to keep abreast of important content. (Your email will not be sold or shared.)
IMPORTANT! If you do not receive a confirmation email, check your spam folder.

Login/Registerfor the forums, and to leave comments that link to your websiteRegister | Login